Electrolytic cell and method of maintaining the efficiency thereof.



WHM. JEWELL. ELECTROLYTIC CELL AND METHOD OF MAINTAINING THE-EFFICIENCY THEREOF.

APPLICATION FILED MMLZ. 1914.

Patented July 6, 1915.

law?

IVs

WITNESSES INVENTIOR Ma. 77:.

' ATTORNEY WILLIAM M. JEWELL, OF CHICAGO, ILLINOIS. ASSIGNOR TO CHLORIDE PROCESS COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.-

ELECTROLYTIC CELL AND METHOD OF MAIIN'TAINING THE EFFICIENCY THEREOF.

' Specification of Letters Patent.

Patented July 6, 1915.

Application filed March 2, 1914. Serial No. 821,978.

To all whom it may concern Be it known that I, ,VVILLIAM M. JEWELL, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Electfolytic Cells and Methods of Maintaining the Efficiency Thereof, of which the following is a specification, reference being had to the accompanying drawings. I

My invention relates to electrolytic cells, and is of especial utility in connection with cells of the character shown and described in Letters Patent No. 1,056,181, granted to me March 18, 1913, in which'the portions of the electrolyte surrounding the anodes and cathodes, respectively, are of different specific gravitie's, the anode liquor being the heavier so that the cathode liquor is, in a sense, carried by the anode liquor, the stratification of the anode and cathode liquors .being preserved by supplying a suitable liquid to the cathode liquor, as required, to keep it lighter than the anode liquor.

In the operation of cells of this character, I have discovered that the efficiency of the cell, in the course of time, tends to deteriorateowing to the formation of hypochlorites or chloratesin the anode liquor, due, apparently, to the migration of the hydroxyl ions which are being constantly carried toward the anodes. The graphite elements composing the anodes are very readily oxidized and destroyed in the presence of hypochlorites or chlorates. I have discovered, further,

that the deterioration referred to may be, to

' a large extent, if not altogether, prevented and the efliciency of the cell very markedly increased, by maintaining a flow of anode liquor from the lower portion of the anode chamber toward the lower portion of the cathode chamber, and particularly below the cathodes therein, this liquor being then withdrawn from the cell and treated to replenish its saline constituents, after which it is returned to the anode chamber. ,The latter step, while advantageous from the standpoint of economical operation of the cell, is

not essential to the generic idea of causing the liquor from the anode chamber to flow toward the cathode chamber and then out of the cell so as to maintain a definite flow of the liquor from the anode chamber toward the cathode chamber. The best results are obtained by maintaining a flow of the liquor through the lower portions of the anode and cathode chambers, then out of the cell and back to the anode chamber after replenishment of its salient constituents; but very satisfactory results are obtained by maintalning such circulation without restoring the strength of the liquor, and also by maintaining the flow from the, anode to the cathode chamber and then out of the cell without returning the liquor to the cell. I believe the increased eflicie cy of the cell due to this mode of operation is due to counteractionof the migration of the hydroxyl ions from the cathode toward the anode chamber, but the fact is, that by the operation described the tendency to form hypochlorites or chlorates' in the anode liquor is,

to a large extent, if not entirely, overcome and the efliciency of the cell very greatly increased.

In addition "to the method described, which forms an important feature of iny present invention, my invention also includes the construction of the cell by which partial plan view, the electrodes being in section; Fig. 4 is a view illustrating oneof the anode units; and Fig. 5 isa bottom view of the anode unit shown in Fig. 4.

Referring to the drawings, 6 indicates the bottom, 78 the side walls, and 9 one of the end walls of the cell, these parts being preferably made of soapstone, or other suitable material.

10 11 indicate two longitudinally-extending partitions, also of soapstone,,,which are disposed adjacent to the side walls 7-8, .respectively, as best shown in Figs. 2 and 3. The space between the partitions 7 and 10 constitutes a chamber A which, in the op eration of the cell, contains a caustic solution, such as sodium hydrate, and into which also the gases generated at the cathodes pass. The space between the wall 8 and the partition 11 is divided by.a horizontal partition 12 into an upper chamber 'B and a lower chamber'G. The upper chamber, in the operation of the cell, is adapted to contain a substantially saturated solution of brine, which constitutes the e1ectrolyte, and is connected with the anode chambers hereinafter described bypassages 13, as shown in Fig. 3. The chamberC is adapted to contain spent brine and is connected with the lower portion of the electrolytic chamber by pipes 14,.the arrangenient'of which will be hereinafter more particularly described.

15 indicates an outlet pipe leading from the lower portion of the chamber C, and 161 indicates an inlet pipe leading to the lower portion of the chamber B.

As shown and described in my patent hereinbefore referred to, the spent brine passing out of the chamber C is conducted through a suitable apparatus where it takes up a fresh supply of salt so that it is restored to the proper strength and-is then reintroduced through the chamber B. As such brine-strengthening apparatus is fully described in my said patent, it is not illustrated herein.

17 indicates a series of vertically-disposed partitions which extend transversely ofthe cell between the partitions 10-11, separating the same into a number of separate compartments, each of which is adapted to contain an operating cell unit comprising anode and cathode chambers.

18 indicates a number of shorter partitions extending downward from the upper part of the cell to a point near the bottom thereof, which divides the several compartments into anode chambers 19 and cathode chambers 20, as best shown in Fig. 1.

21 indicates the anodes, which ektend down into the anode chambers, each of said chambers containing a plurality of anodes in the form of rods, of carbon or other suitable material, the several anodes in each chamber being connected to a-common supporting slab or bar 22, which is also preferably made of carbon and not only supports the anodes but forms a cover for the anode chamber. The anodes are preferablv secured to the bar 22 by providing them with screw threads so that they may be screwed into threaded sockets in sa d bar, as best shown in Fig. 2. The arrangement of the several anodes forming each unit is best shown in Fig. 4.

23 indicates the cathodes, which are sulistan'tia-lly like the anodes and are made of the same material but are somewhat shorter so that they do not project down into the cathode chamber as far as the anodes projectinto the anode chamber, as is best shown in Fig. 1. The cathodes of each unit are secured to a supporting-bar 24. which forms a cover for the cathodc chamber, so that the before entering'the pipes 14 through which it is conducted away for the replenishing treatment. The pipes 14 are placed low ,enough so that this flow of anode liquor from the anode chambers is independent of the outflow of cathode liquor, which is otherwise provided for, and does not disturb or mingle with the liquor in the cathode chambers to any material extent, and consequently is maintained comparatively free from the caustic solution formed in the cathode chambers. By instituting this flow of the liquor in the anode chambers, the formation of hypochlorites or chlorates in the anode liquor, as hereinbefore explained, is prevented, and the eiiiciency of the ml] is very greatly increased. The liquor in the anode chambers is heavier than that in the cathode chambers, and the relative specific gravities of these liquors is maintained from time to time, as may be necessary, by supplying water to the cathode chambers. preferably through funnels 25 provided for that purpose.

26 indicates ducts leading from the upper portions of the several cathode chambers to the chamber A, as shown in Fig. 3, such ducts being provided to conduct the hydrogen formed in the cathode chambers into said chamber A, whence it may pass out through a pipe 27 provided for that purpose, as shown in Fig. 2.

28 indicates passages extending through the partition 10 below the level of the liquor in the cathode chambers for conducting the caustic solution into the chamber A.

29 indicates an outlet pipe leading from the upper portion of the chamber A, which pipe is placed at the level at which it is desired to maintain the liquor in the cathode chambers.

30 indicates ducts leading from the upper portion of the anode chambers to the upper portion of the chamber B for conducting chlorin from said anode chambers to the chamber B, and 31 indicates a discharge pipe leading from the chamber B for the discharge of the chlorin therefrom.

By circulating the anode liquor in the manner described, a very rapid rate of flowcan be maintained without adding any appreciable amount of salt or chlorin to the cathode products, and I am able to obtain produce.

ode chambers,

very high efliciencies both in chlorin and caustic soda production, using an electrolyte consisting of a saturated solution of common salt. Of course, the cell may also be used with'some other electrolyte and with electrodes of other materials, depending upon' the products which it is desired to and cathode elements arranged vertically, in the manner described, I also obtain much better results thanwhere horizontal electrodes are used, as the elec: trode area, being gaseous products of the electrolysis are very readily eliminated and do not adhere to the electrodes. A further advantage in using cathode elements ofthis form is that only a very small percentage of the caustic soda- By using anode 15 produced in the lower port-ion of the cathand therefore the cathode liquor has less tendency tobecome saturated and gravitate toward the bottom of the cell or to flow toward the anode compartments. Where horizontal electrodes are used, the

gases do not readily pass off as formed, thus increasing the resistance of the cell and lowering its efiiciency; also with horizontal cathodes the tendency isto produce a heavy caustic liquor at or below the lower portions of the cathodes, leaving the cathode liquor above the cathodes comparatively light If this condition is allowed to go on, the'caustic liquor thus produced at the under sides of the cathodes becomes heavier than the brine and unless interfered with wou d find its way into the anode chambers where it would form hypochlorites or chlorates, with the objectionable results hereinbefore described.

By using electrodes consisting of a p'lurality of rods assembled in units as described, the electric current may travel from point to point, or end to end, of the graphite rods, and this by reducing the resistance in the cell produces better results and permits of the substitution of ccnductive materials for the partitions 18 instead of partitions made of di-electric material, thereby increasing the efiiciency of the cell by reducing the resistance ofi'ered to the passage of the current from the anode to the cathode chambers.

While my improved cell may be very efliciently employed to generate chloringas and caustic solution, it may be used for any other purpose to which it is adapted.

That which I claim as my invention, and desire to secure by Letters Patent, is,

1. The method of maintaining the efliciency of an electrolytic cell of the type described, which consists in causing liquor I from the anode chamber to flow toward the 5. liquor.

cathode therein,

below the level of the and then out of the cell the outflow of cathode cathode chamber independently of substantially vertical, the

returning it tothe then out of the cell independently of the outflow of cathode liquor.

4. The method of maintaining the efiiciency of an electrolytic cell of the type described, which consists in causing liquor from the anode chamber to flow toward the cathode chamber below the level of the cathode therein, and then out of the cell independently of the and then re-introducing the liquor into the anode chamber.

5. The method of maintaining the efliciency of an electrolytic cell having anode and cathode chambers disposed side by side, and in which the electrolyte comprises a heavier anode liquor and a lighter cathode liquor, which consists in maintaining a flow of liquor from the lower portion of the anode chamber into the lower portion of the cathode chamber and then out of(the cell independently of the outflow of cathode li( uor.

6. The method of maintaining the efficiency of an electrolytic cell in which the electrolyte comprises,a heavieranode liquor and a lighter cathode liquor, arranged in adjacent chambers, which consists in discharging liquor from the lower portion of the anode chamber through the lower portion of the cathode chamber independently of the outflow of cathode liquor, and then .re-introducing it into the anode chamber.

7. The method of maintaining the efiiciency of an electrolytic cell in which the electrolyte comprises a heavier anode liquor and a lighter cathode liquor, arranged in adjacent chambers, which consists in discharging liquor from the anode chamber through the lower portion of the cathode chamber, restoring the strength of the discharged liquor, and then re-introducing it into the anode chamber.

8. The method of maintaining the efficiency of an electrolytic cell having anode and cathode chambers disposed side by side, and in which the electrolyte comprises a heavier anode liquor and a lighter cathode liquor, which consists in maintaining a dis charge of liquor from the lower portion of the anode chamber through the lower portipn of the cathode chamb strength of the discharged the lower portion of liquor, and then anode chamber.

outflow of cathode liquor,

er, restoring the ltll l ciency of an electrolytic cell havinganode and cathode chambers disposed side by side, and in which the electrolyte comprises a heavier anode liquor and a lighter cathode liquor, which consists in maintaining a discharge of liquor from the cell across the cathode chamber below the level of the cathode therein and independently of the outflow of cathode liquor.

10; An electrolytic cell comprising anode and cathode chambers adapted to contain a heavier anode liquor and a lighter cathode the level of the cathode therein and thence liquor, an anode in the anode chamber, a

cathode in the cathode chamber, and means for causing liquor to flow from the anode chamber toward the cathode chamber below out of the cell independently of the outflow of cathode liquor.

'11. An electrolytic cell comprising anode and cathode chambers adapted to contain a heavier anode liquor and a lighter cathode liquor, an anode in the anode chamber, a cathode in the cathode chamber, and means for causing liquor frbm the lower portion of the anode chamber to flow across the lower portion ofthe cathode chamber and then out of the cell independently of the outflow of cathode liquor.

12. An electrolytic cell comprising anode and cathode chambers adapted to contain a heavier anode liquor and a lighter cathode liquor, the lower portion of the {anode chamber communicating directly with the lower portion of the cathode chamber, an anode in the anode chamber, a cathode in the cathode chamber, and an outlet communicatingwith the lower portion of the cathode chamber for causing liquor to flow from the anode chamber into the lower portion of the cathode chamber and then out of the cell independently of the outflow of cathode liquor.

13. Anyolectrolytic cell comprising a receptacle having anode and cathode chambers disposed side by side, a partition separating the upper portions of said chambers from each other and allowing communiczv'.

tion between the lower portions of said chambers, and depending rods in said chainbers, respectively forming anodes and cathodes.

ll. An electrolytic cell comprising a receptacle having anode and cathodechambers disposed side by side, a partition separating the upper portions of said chambers from each other and allowing communication between the lower portions of said chambers, and depending rods in said chambers, respectively forming anodes and cathodes, the cathodes being shorter than the anodes, and an outlet communicating with the lower portion of the cathode chamber below the cathode therein.

15. An electrolytic cell, comprising anode and cathode chambers disposed adjacent to each other and having a communicating opening in the lower portions thereof, an anode and a cathode in said chambers, respectively, above said opening, and an outlet for the liquor comumnicating with the lower portion of the cathode chamber whereby liquor may flow from the anode to the cathode chambers, and then out of the cell.

WILLIAM M. J EWELL.

\Vitncsses OMAR H. JEWELL, Join: L. Jac rsox.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C." 

